1. Field of the Invention
This invention relates to a method of producing hydrogen for use in a refinery processing heavy crude oil. In one aspect, the invention relates to a method of producing hydrogen by processing the bottoms of a solvent deasphalting process into hydrogen using partial oxidation methods. In another aspect, the invention relates to an integrated system for producing hydrogen from the bottoms of a solvent desasphalting system in a refinery and using the H.sub.2 in the hydroprocessing operations of the refinery.
2. Description of Related Art
Heavy crude oil is generally produced in remote locations, making it impractical to refine the oil at those locations. In such instances, the heavy crude oil is generally transported to a refinery where the crude oil is refined into useful products such as naphtha, kerosene, diesel fuel, fuel oils, gasoline, lube oil, and the like. ("Heavy crude oil" is defined as an oil having an API gravity of about 6 to about 20 API and a high asphaltene content.)
There is a need for large amounts of cheap hydrogen in the refining of heavy crudes. These crudes generally contain large amounts of sulfur, and must be desulfurized which is generally done by hydrogen treatments. The primary product of heavy crude is gas oil which requires significant hydrotreating or hydroprocessing which also uses large amounts of hydrogen. Other refinery operations that use hydrogen are treatments to remove nitrogen, oxygen compounds and to saturate olefins. Moreover, the hydrocracking of the large molecules in the heavy oil requires large amounts of hydrogen.
U.S. patent application Ser. No. 08/927,427, filed Sep. 11, 1997, and entitled "Method for Transporting a Heavy Crude Oil Produced via a Wellbore from a Subterranean Formation to a Market Location and Converting it into a Distillate Product Stream Using a Solvent Deasphalting Process" discloses a method for treating heavy crude where deasphalted heavy crude bottoms are used as a fuel to generate steam in a boiler like reactor for use in the crude distillation and deasphalting operations and for generating of electricity. The flue gas from the fuel combustion is further treated in a water shift reactor to produce hydrogen for use in refining operation such as hydrogenation. However this process produces relatively small amounts of hydrogen because the flue gas contains only small amounts of CO which is the reactant in the water shift reaction to produce the H.sub.2.